What to do if a CMYK image has no profile?
Hello, I’d like to find a way to manage images without ICC profiles ; the only way I do that actually is by converting to profile in various ICC profils and use the preview to see the alterations. But it’s hazardous and I’d like to know if there could be another way to give a chance to those images… -- Serge Paulus Teacher, ESA Saint-Luc - Ihecs Adobe Education Leader Adobe Certified Photoshop Expert, Adobe Certified Instructor www.serge-paulus.be +32 474 63 67 44
I don't believe images can be managed without ICC profiles in Photoshop? When you view images in Photoshop, there is *always* one profile implicitely or explicitely assigned to the image. / Roger -----Original Message----- From: colorsync-users-bounces+graxx=videotron.ca@lists.apple.com [mailto:colorsync-users-bounces+graxx=videotron.ca@lists.apple.com] On Behalf Of Serge Paulus Sent: 7 janvier 2016 18:21 To: colorsync-users@lists.apple.com Subject: What to do if a CMYK image has no profile? Hello, I’d like to find a way to manage images without ICC profiles ; the only way I do that actually is by converting to profile in various ICC profils and use the preview to see the alterations. But it’s hazardous and I’d like to know if there could be another way to give a chance to those images… -- Serge Paulus Teacher, ESA Saint-Luc - Ihecs Adobe Education Leader Adobe Certified Photoshop Expert, Adobe Certified Instructor www.serge-paulus.be +32 474 63 67 44
On Jan 7, 2016, at 4:42 PM, Roger Breton <graxx@videotron.ca> wrote:
I don't believe images can be managed without ICC profiles in Photoshop?
When you view images in Photoshop, there is *always* one profile implicitely or explicitely assigned to the image.
Indeed, the very idea of a CYMK or RGB image without a profile is as meaningless as a length without units. How long is your paper? 17? 17 _what?_ Inches, centimeters, feet, smoots? At the very least, you need the absolute values of the primaries and a not-miserable guess of a gamma (or equivalent) curve. Get that much right and it’s “close enough” for everything but critical work. Lacking that...you’re down to one of two options. Arbitrarily assign a least-insane default (region-specific CMYK such as SWOP or FOGRA or whatever, sRGB for RGB)...or start by such an assignment and then start fiddling around with sliders until you’re less unhappy with what you see than when you started. b&
On 7 Jan 2016, at 23:21, Serge Paulus <sp@serge-paulus.be> wrote:
I’d like to find a way to manage images without ICC profiles ; the only way I do that actually is by converting to profile in various ICC profils and use the preview to see the alterations. But it’s hazardous and I’d like to know if there could be another way to give a chance to those images…
Hope you mean “assign” and not “convert” Serge? Mystery CMYK shouldn’t be that hard to work with — even without profiles you can usually tell what sort of CMYK device it was converted for just by looking at the separations. Most can be repurposed for a different CMYK device in a few minutes using curves. If you need to make big changes then I don’t think Photoshop is a suitable tool. Professional pre-press kit allows you to repurpose CMYK without completely trashing useful information from original separations. If the reproduction quality is super-critical then I’d always recommend proofing before editing the images. -- Martin Orpen Idea Digital Imaging Ltd
participants (4)
-
Ben Goren
-
Martin Orpen
-
Roger Breton
-
Serge Paulus